Counter coil construction



1933' T. B. MACKENZIE COUNTER c011. CONSTRUCTION Filed May 9, 1931 2 Sheets-Sheet 1 Nov. 21, 1933. 'r. B. MACKENZIE v COUNTER COIL CONSTRUCTION Filed May 9, 1951 2 sheets sheet 2 A TTORNEY.

Patented Nov. 21, 1933 uurrao ranger conN'rEa COIL coNs'raUorIoN 7 Thomas B. Mackenzie, Los Angeles, Calif., as-

Signor to Baker Ice Ma Neblx, a corporation of No no Ce. line, Omaha, braslia Application May 9, 1931. Serial No. 536,149

3 Claims. (Cl. 62-S9.6)

This invention relates to refrigeration appara tus and particularly to a coil arrangement for refrigerated display cases, counters and the like, such as are employed in meat markets and other places requiring display of merchandise independent of the usual refrigerated storage rooms.

Ordinarily in retail markets, the storage rooms, which may be an ordinary walk-in refrigerator, and the display counters are supplied with a single automatic refrigerating machine controlled by a thermostat placed in the walk-in refrigerator, and therefore, operation of the rnachine is entirely independent of the temperature in the display case. Consequently, due to the large cubic capacity of the refrigerator and its well insulated wall surface, as contrasted with the relatively small cubic space in the dispay cases and their relatively poorly insulated walls, the temperature during the shut-down periods of the machine raises much faster in the display counters than in the refrigerator, thus the counters require a longer running period of the machine than the refrigerator.

It is therefore the object of this invention to provide a coil construction which permits a refrigerant hold-over for the display case during the period that the refrigerating machine is not operating.

It is a further object of the invention to provide a hold-over arrangement requiring a relatively small portion of the available space in the counter and which may be positioned for the best refrigeration res lts without sacrificing storage space or visibility of merchandise.

is also an object of the invention to provide a coil arrangement with a minimum number of threaded connections to permit ready installation in the existing display counters.

ther objects of theinvention are to provide a refrigeration coil and hold-over arrangement which may be kept in efhcient operating and sanitary conditions.

In accomplishing these and other objects of the invention, I have provided improved details of structure, the preferred form of which is illustrated in the accompanying drawings, Wherel l is a perspective view of a display counter equipped with a hold-over coil arrangement constructed in accordance with my invention.

Fig. 2 is a vertical cross secticnalview through the counter on the line 2-2, Fig. 1.

Fig. 3 is a sectional view through one of the hold-over coils on the line 3-3, Fig. 4, particularly illustrating the trap for retaining a quantity of liquid refrigerant therein, to prolong the cooling effect during shut down periods.

Fig. 4 is a detail longitudinal sectional View through one of the coils on the line 44, Fig. 2.

Fig. 5 is a cross sectional view through a counter illustrating a modified form of coil arrangenlent.

Fig. 6 is a detail perspective view of the coil arrangement shown in Fig. 5. Fig. '7 is diagrammaticview of a complete sys tern illustrating the course of refrigerant throug a counter and walk-in refrigerator. Referring more in detail to the drawings: I

1 designates a refrigerator display case comprising an insulated floor 2, a counter portion 3, an inclined rear port-ion d terminating in an offset counter 5, a front display wall 6 consisting of a plurality of spaced panes '7, andiinsulated end walls 8 and 9.

Secured to the under surface of the counter portion 3 and depending therefrom, are spaced brackets 10, each comprising a plate portion 11 through which fastening devices 12 are projected to secure the brackets, and curvedarrns l3-and 14: extending downwardly and laterally of the plate portions and terminating in curved seats 15 and 16 for supporting a set of refrigeration coils generally designated 17. i

The coils 17 comprise apair of pipesections 18 and' 19 of sufficient-length to extend approximately from one end of the counter to: the other and are of relatively large diameter..-in order to provide refrigerant expansion chambers adapted. for the retention of a quantity of the refrigerant, as later described. A

The pipe sections are preferably connected at one end by a pipe 20 communicatingtherewith, at points above theirhorizontal' diameters" and the opposite ends are provided with inlet and outlet connections, preferably comprising nipples 21 and 22 welded in the lower wallsof the sections and projecting upwardly therein to substantially their axes, thereby'providing traps or Weirs over which the liquid must flow in entering and leaving the sections. A quantity'of refrigerant, designated 23 and 2,'is thus trapped in the coils to provide a hold-over feature for the coils to continue the refrigeration process after the refri eration machine which supplies refrigerant, as later described, is shut down. Connected with the inlet nipple 21 is an inlet pipe 25 leading from the refrigeration machine and connected with the nipple 22 is a refrigerant outlet pipe 26 through which the'surplus refrigi erant inay flow to a second coil unit located in the offset counter portion'and generally designated 27. This coil unit is similar to that above describecLin that it includes a pair of pipe sections 28 and 29 extending longitudinally-of the counter and which are supported by comple-' mentary brackets 30 having curved seats 31 and 32-for-receivirig the sections. A v

The pipe 26 preferably communicates with one end of the pipe 28 at a point on its horizontal diameter. and the opposite end of the pipe 28 communicates with the other pipe section 29 by a transfer pipe 33 through which the liquid may flow for discharge through an outlet nipple 34 projecting into the section 29 complementary to the nipples previously described, an outlet pipe 35 being threaded into the nipple for returning the expanded refrigerant to the compressor.

Fig. 5 shows a modified form of coil arrange ment wherein the upper coil consists of a single pipe 36 having an inlet at one end comprising an L-shaped nipple 3'7 communicating with the pipe above its horizontal diameter, and its outlet comprises a similar L-shaped nipple 38 which is connected by a pipe 39 with a lower pipe section 40 positioned in the rear offset portion of the counter similar to'the sections in the preferred form.

The refrigerant is supplied to the upper coil, through the pipe 25 or 37 as the case may be, through a conduit 41 from the receiver of a refrigeration machine 42, provided with the usual expansion or like valve (not shown) and passes from the lower coil through coils 43 in the storage cooler or walk-in refrigerator 44 back to the machine.

A thermostatically operating device 45 may be subject to changes of temperature in the refrigerator 44 for controlling operation of the machine.

The counter coil pipes of each set may be of the same size, the rear pipe 29 of the lower set being preferably larger than the pipe 28 as shown in Figs. 1 and 2 and wholly contained in a recess under the offset counter portion 5.

In a coil arrangement constructed and assembled as described, liquid refrigerant is admitted from the supply through the pipe 25 and overflows over the weir-like upper edge of the nipple 21 into the pipe section 18 until the level of the refrigerant reaches the height of the outlet connection 20 when the refrigerant flows into the other section 19 to fill that section to a level controlled by the height of the nipple 22. The refrigerant then overflows into the pipe section 28 filling that section to the height of the pipe 33 wherein it flows into the other section 29 to a level controlled by the nipple 34.

Thus it is apparent that due to the arrangement of the inlet and outlet connections, a quantity of liquid stands in each of the pipe sections to maintain the coils in semi-flooded condition after the refrigerating machine has shut down, to hold over the refrigerant and continue the process of vaporization and maintain a refrigerating condition in the case until refrigerant has evaporated. However, the capacities of the pipes are such as to retain sufficient amount of refrigerant to continue the cooling process up to the time when the temperature in the walk-in refrigerator again starts operation of the machine.

As soon as the refrigeration machine begins operation, the pipe sections are again replen ished with refrigerant to hold over the next idle period of the machine.

It is apparent, that by locating the sets of coils at different elevations, a circulation is induced to maintain subsequent uniform temperatures, since there is a tendency for the lower part of the counter to be colder than the top. Pressure in the coils will correspond to a mean temperature between the sets of coils. The top pipe, being slightly warmer, will cause the trapped liquid to evaporate and produce a cooling effect. The vapors will then pass over to the lower pipes, condense and revaporize.

A similar series of operations occurs between the counter coils and the coils 43 in the refrigerator 44. The counter warms up faster than the refrigerator, and the refrigerant therefore evaporates faster in the counter coils and the vapor passes over into the coils in the refrigerator, Where it condenses.

Additional refrigeration is thus provided during cessation of operation of the machine not only by the recondensation action in the lower counter coils, but by virtue of vapors from the counter coils being condensed in the refrigerator coils.

When it is desired to defrost the coils, the pressure is allowed to rise to around pounds and the counter doors are opened to permit entrance of warm air for effecting melting of the frost.

Coils constructed as described may be placed where they are most efficient without interfering with the display. Even in such positions, only enough of the cooling surface is visible through the glass panel to add to the attractiveness of the counter since the frosted surface advertises at-a glance, the refrigerated condition of the counter.

The coils may be continuous, as shown, or they may be bent to conform to the shape of the counter, thus eliminating a separate coil unit for angular portions of the counter.

What I claim and desire to secure by Letters Patent is:

1. Apparatus of the character described including a machine for circulating a refrigerant, a refrigerator, a coil in the refrigerator, a refrigerant return line leading from the refrigerator coil to the machine, a display case, a coil in the display case, a pipe connecting the machine with the coil in the display case, means connecting the coil in the display case with the coil in the refrigerator, means in the refrigerator for controlling operation of the machine, and means for trapping refrigerant in the coil in the display case.

2. In combination with a storage refrigerator and a display case, a coil in the storage refrigerator, a machine responsive to change in temperature in the storage refrigerator for supplying refrigerant to the coil, a coil in the display case having inlet from said machine and outlet to the coil in the storage refrigerator above the bottom of said coil to provide storage of refrigerant in said coil for continued cooling of the display case while the machine is idle.

3. In combination with a storage refrigerator and a display case, a coil in the storage refrigerator, a machine responsive to change in temperature in the storage refrigerator for supplying refrigerant to the coil, a coil in the display case, a supply line leading from the machine to the inlet end of the coil in the display case, a return line leading from the outlet end of the coil in the display case to the coil in the storage refrigerator, and weirs associated with said inlet and outlet lines for trapping liquid refrigerant in the coil in the display case to provide continued cooling of the display case while the machine is idle.

THOMAS B. MACKENZIE. 

